The present invention relates to a deep sea mining method comprising, providing a deep sea mining system for mining matter from a bottom of a body of water.
GB2495287 relates to a riser system for transporting a slurry from a position adjacent to the seabed to a position adjacent to the sea surface. In order to be flexible in production, GB2495287 teaches to provide first and second risers; a slurry pump system to transport slurry up one of the risers; and a waste water pump system to return waste water down one of the risers. The slurry pump system and the waste water pump system are selectively connectable to each of the risers to allow each riser to be either a slurry riser or a waste water riser.
WO 2010/092145 A1 is another example having a riser conduit and a tailings stream. Tailings are just disposed via a disposal pipe, see FIG. 3. During operations, tailings will accumulate and may easily cause problems in that a site of interest is covered.
US2012/234552 A1 relates to a system for harvesting natural gas from a clathrate deposit. A pipe or tube is suggested for distributing the water back into the ocean away from the harvesting location. In addition, it is also suggested to pump the debris through a particulate disposal system for returning the debris to the sea floor at a location that is removed from the clathrate deposit. Still over time, debris will accumulate and may easily cause problems.
WO 2011/072963 A1 relates to a method of converting a methane containing hydrate deposit in the water bottom into a marketable product. FIG. 2 shows a tailing disposal pipe to a site. Again, over time, debris will accumulate and may easily cause problems.
US2009/284068 A1 relates to a method of monitoring and adjusting a flow rate of a slurry in a riser system of a deep sea mining system. It is suggested to discharge waste water at the sea floor level.
In conclusion, where the prior art disposes debris rather than water alone, it is disposed at a fixed location such that over time, debris will accumulate and may easily cause problems.